MCQOPTIONS
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MCQOPTIONS
This section includes 36 Mcqs, each offering curated multiple-choice questions to sharpen your Life Sciences knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The pathway of a tRNA during polypeptide elongation on the ribosome is |
| A. | A site → P site → E site |
| B. | P site → entry site → exit site |
| C. | A site → P site → entry site |
| D. | P site → A site → E site |
| Answer» B. P site → entry site → exit site | |
| 2. |
Degenerated codon differs mostly in |
| A. | the identities of their second base |
| B. | the identities of their third base |
| C. | the wobble position |
| D. | both (b) and (c) |
| Answer» E. | |
| 3. |
Which of the following has unusual bases? |
| A. | mRNA |
| B. | tRNA |
| C. | rRNA |
| D. | hnRNA |
| Answer» C. rRNA | |
| 4. |
The site on a bacterial chromosome that marks the termination point for chromosome replication is called |
| A. | ter |
| B. | a stop codon. |
| C. | a stem-loop |
| D. | pau |
| Answer» B. a stop codon. | |
| 5. |
Which of the following inhibits initiation at higher concentrations? |
| A. | Chloramphenicol |
| B. | Streptomycin |
| C. | Diphtheria toxin |
| D. | Ricin |
| Answer» C. Diphtheria toxin | |
| 6. |
Which of the following catalyzes ADP-ribosylation of a diphthamide residue? |
| A. | Chloramphenicol |
| B. | Cycloheximide |
| C. | Diphtheria toxin |
| D. | Ricin |
| Answer» D. Ricin | |
| 7. |
The eukaryotic mRNA binding to the ribosomes is facilitated by ____________ |
| A. | T-RNA |
| B. | Poly-A tail |
| C. | Shine Dalgarno sequence |
| D. | 7-methyl guanosine cap |
| Answer» E. | |
| 8. |
What is the role of small nuclear RNAs in protein synthesis? |
| A. | It translates genetic code to a specific amino acid |
| B. | It modifies mRNA molecules prior to protein synthesis |
| C. | It provides a genetic blueprint for the protein |
| D. | It catalyzes the process |
| Answer» C. It provides a genetic blueprint for the protein | |
| 9. |
What is the role of mRNA in protein synthesis? |
| A. | It translates genetic code to a specific amino acid |
| B. | It modifies mRNA molecules prior to protein synthesis |
| C. | It provides a genetic blueprint for the protein |
| D. | It catalyzes the process |
| Answer» D. It catalyzes the process | |
| 10. |
Bacteria have ____________ |
| A. | 70S ribosomes |
| B. | 60S ribosomes |
| C. | 50S ribosomes |
| D. | 80S ribosomes |
| Answer» B. 60S ribosomes | |
| 11. |
Which of the following inhibitor block translation in eukaryotes? |
| A. | Cyclohexamine |
| B. | Tetracycline |
| C. | Puromycin |
| D. | Streptomycin |
| Answer» B. Tetracycline | |
| 12. |
Name the inhibitor which blocks translation in both prokaryotes as well as eukaryotes? |
| A. | Chlorophenicol |
| B. | Tetracycline |
| C. | Puromycin |
| D. | Streptomycin |
| Answer» D. Streptomycin | |
| 13. |
Which of the following recognize a specific amino acid and its cognate t-RNA molecule? |
| A. | t-RNA synthetase |
| B. | Ribososme |
| C. | r-RNA |
| D. | Topoisomerase |
| Answer» B. Ribososme | |
| 14. |
Who explained the wobble hypothesis? |
| A. | Darwin |
| B. | Watson and Crick |
| C. | Samuel B. Weiss |
| D. | Nirenberg |
| Answer» C. Samuel B. Weiss | |
| 15. |
WHICH_OF_THE_FOLLOWING_RECOGNIZE_A_SPECIFIC_AMINO_ACID_AND_ITS_COGNATE_T-RNA_MOLECULE??$ |
| A. | t-RNA synthetase |
| B. | Ribososme |
| C. | r-RNA |
| D. | Topoisomerase |
| Answer» B. Ribososme | |
| 16. |
WHICH_OF_THE_FOLLOWING_CATALYZES_ADP-RIBOSYLATION_OF_A_DIPHTHAMIDE_RESIDUE??$ |
| A. | Chloramphenicol |
| B. | Cycloheximide |
| C. | Diphtheria toxin |
| D. | Ricin |
| Answer» D. Ricin | |
| 17. |
WHO_EXPLAINED_THE_WOBBLE_HYPOTHESIS??$ |
| A. | Darwin |
| B. | Watson and Crick |
| C. | Samuel B. Weiss |
| D. | Nirenberg |
| Answer» C. Samuel B. Weiss | |
| 18. |
Which of the following inhibitor block translation in eukaryotes?$ |
| A. | Cyclohexamine |
| B. | Tetracycline |
| C. | Puromycin |
| D. | Streptomycin |
| Answer» B. Tetracycline | |
| 19. |
Name the inhibitor which blocks translation in both prokaryotes as well as eukaryotes?$ |
| A. | Chlorophenicol |
| B. | Tetracycline |
| C. | Puromycin |
| D. | Streptomycin |
| Answer» D. Streptomycin | |
| 20. |
Which of the following inhibits initiation at higher concentrations?$ |
| A. | Chloramphenicol |
| B. | Streptomycin |
| C. | Diphtheria toxin |
| D. | Ricin |
| Answer» C. Diphtheria toxin | |
| 21. |
Name the drug which inhibits the initiation step of translation. |
| A. | Cyclohexamine |
| B. | Tetracycline |
| C. | Ricin |
| D. | Streptomycin |
| Answer» E. | |
| 22. |
Which of the following blocks the peptidyl transferase of 80S eukaryotic ribosomes? |
| A. | Chloramphenicol |
| B. | Cycloheximide |
| C. | Diphtheria toxin |
| D. | Ricin |
| Answer» C. Diphtheria toxin | |
| 23. |
Which of the following is not true to the nature of the genetic code? |
| A. | Codon is triplet |
| B. | Codons are commaless |
| C. | Codons are overlapping |
| D. | Codons are universal |
| Answer» D. Codons are universal | |
| 24. |
The eukaryotic mRNA binding to the ribosomes is facilitated by |
| A. | T-RNA |
| B. | Poly-A tail |
| C. | Shine Dalgarno sequence |
| D. | 7-methyl guanosine cap |
| Answer» E. | |
| 25. |
Mark the one, which is NOT a stop codon? |
| A. | UAA |
| B. | UAG |
| C. | UGA |
| D. | GGA |
| Answer» E. | |
| 26. |
The role of small nuclear RNAs in protein synthesis is |
| A. | It translates genetic code to a specific amino acid |
| B. | It modifies mRNA molecules prior to protein synthesis |
| C. | It provides genetic blueprint for the protein |
| D. | It catalyzes the process |
| Answer» C. It provides genetic blueprint for the protein | |
| 27. |
Which of the following is considered as a start codon? |
| A. | AUG |
| B. | GUG |
| C. | UAG |
| D. | AGG |
| Answer» B. GUG | |
| 28. |
The role of mRNA in protein synthesis is |
| A. | It translates genetic code to a specific amino acid |
| B. | It modifies mRNA molecules prior to protein synthesis |
| C. | It provides genetic blueprint for the protein |
| D. | It catalyzes the process |
| Answer» D. It catalyzes the process | |
| 29. |
Name the sequence of RNA, which is recognized by a small subunit of the ribosome. |
| A. | Rho utilization site |
| B. | Downstream sequence |
| C. | Upstream sequence |
| D. | Shine Dalgarno sequence |
| Answer» E. | |
| 30. |
In how many steps protein biosynthesis takes place? |
| A. | 2 |
| B. | 3 |
| C. | 4 |
| D. | 5 |
| Answer» E. | |
| 31. |
What is the size of the prokaryotic ribosome? |
| A. | 80S |
| B. | 70S |
| C. | 40S |
| D. | 60S |
| Answer» C. 40S | |
| 32. |
Which is the third elongation step in bacteria? |
| A. | Peptide bond formation |
| B. | Binding of an incoming aminoacyl t-RNA |
| C. | Translocation |
| D. | None |
| Answer» D. None | |
| 33. |
The following set of RNA is required in the translation process except one, mark the INCORRECT? |
| A. | Si RNA |
| B. | rRNA |
| C. | mRNA |
| D. | tRNA |
| Answer» B. rRNA | |
| 34. |
Which of the following inactivates the 60S subunit of eukaryotic ribosomes? |
| A. | Chloramphenicol |
| B. | Cycloheximide |
| C. | Diphtheria toxin |
| D. | Ricin |
| Answer» E. | |
| 35. |
tRNA has peptidal transferase activity. |
| A. | True |
| B. | False |
| Answer» C. | |
| 36. |
Conversion of messages carried by mRNA into amino acid sequences is called___________ |
| A. | Replication |
| B. | DNA repair |
| C. | Translation |
| D. | Transcription |
| Answer» D. Transcription | |